1. Technical Field
The present invention relates to a communication device and a communication method using ultrasonic waves.
2. Related Art
A diver under water needs to communication with other divers in order to secure his or her own safety. As a device which carries out communication using ultrasonic waves under water, a communication device is proposed which carries out full-duplex bidirectional communication via ultrasonic waves of two frequencies, as disclosed in JP-A-11-122690.
However, in order to carry out full-duplex bidirectional communication, it is necessary to provide both an ultrasonic oscillating unit which generates a frequency for transmission and an ultrasonic oscillating unit which generates a frequency for reception. The communication device is thus increased in size.